Charging hopper for electric furnaces



June 1 1926. 1,586,588

c. T. THoRssELL Er AL CHARGING HOPPER FOR ELECTRIGFURNACES June l1 1926.

C. T. THORSSELL ET AL CHARGING HOPPER FOR ELECTRIC FURNACES Filed June 20, 1921 2 Sheets-Sheet Patented June 1, 1926.

UNITED .STATES y x 1,586,588 PATENT- OFFICE.

CBL THEODOR THOBSSELL, EBEE yCHRIS!!!IAN BECK-FE11S, AND EENS-T ERIK DAVID EDLUNDH, 0F GOTTENBORG', -STTEDEN'.

Application and :une zo,

Our invention comprises improvements in charging devices for electric furnacesn and the object of the invention is to eliminate the disadvantages incident to the collecting of the escaping gases.

In a furnace with uniform gas generation if the mass to be treated is carried downwards, while the escaping gases pass in the opposite direction and preheat the materlal, the velocity of the latter will be reduced on account of the frictional resistance against the walls causing the mass here to be heated to a higher temperature in such away that the temperature in a horizontal layer becomes .different at the middle and at the sides. 1f the material is particularly sensitive to such an irregularity of the temperature this disadvantage maybe disastrous. Besides, the materialmust be stirred repeatedly along the furnace walls and in front of the electrodes placed in the walls, and when the temperature is measured by means Vof measuring rods, holes must be provided for these rods. At such stirrlng and measuring of the temperature the shutters must be opened and thus the gasescapes. 0n the other hand, if receptacles for the material 'are to be arranged above the furnace in order to save working power it is difficult to provide such without colliding with thev shutters and holes mentioned.

These inconveniences are remedied by the present invention which is characterized by' a device allowing the material to pass downwards along the sides of the furnace while the gas is taken out at the centre.. Stirrlng holes and the like may be arranged in such l. Way that they may be opened without any considerable loss of gas. Further the preheating of the material passing through the furnace is most efficient at the centre of the furnace while the material at the side walls of the furnace, which material is not so much or-not at all preheated by the escaping gases, endures a stronger heating and thus thetemperature is equalized in such a way that it becomes uniform through the whole inner cross-section of the furnace.

' By arranging valves controllable from the outsidein the lower part of the gas outlet the gas current can be controlled and also the heat conditions in the furnace in some measure regulated in such a way that, if for instance the temperature in a certain part of the furnace is found to be too high, the hot 1921, Serial No. 479,071.

gases may be 4directed through other parts of the material. By dividing the gas chamber 1n sections each provided with a separate outlet and a separa-te controlling valve the same result can be attained.

One form of the invention is shown in the accompanying drawings, in which:

Fig. 1 is a section on line 1 1 of Fig. 3.

Fig. 2 is a section Online 2 2 of Fig. 3.

Fig. 3 is a section on line 3 3 of Figfl.

Fig. 4 is a plan view of the apparatus.

.On the shell plate 2 extending above the upper rectangular part 1 of the furnace two charging hoppers 3 or the like are provided for the material to be treated in the furnace. Under these charging hoppers a distributing plate 4 for the material is arranged, said plate being roof-shaped and having its lower edge at a suitable distance from the shell plate 2.` The distributing plate 4 is extended downwards with four vertical sides 5 between which and the furnace fwalls the material passes down into the furnace-from theA charging hoppers 3. Thus the material introduced into the furnace passes only along the side walls of the furjnace, and the upper surface of the material will form a ditch-shaped cave 6 in the center of the furnace under the distributing plates 4 and 5. The gas outlet is arranged inside of the distributing roof and consists of a hood 7 extending from the lower edges of the-distributing plates 5 and converging upwards where it 1s connected with an outlet 'pipe 8. VStirring holes 9 and holes 9 for measuring the temperature are provided. By means of short vertical plates as 10 arranged across the charging passages each stirring hole is separated from the neighbouring hole in such a manner that the leaking of as at the stirring operation will be essentia ly reduced and eventual gas eXplosions localized that is in the sections 10. The distributing plate and the hood of the gas outlet may also be combined in such a way that a common sheet for them both is used, las indicated at 11.

By this arrangement the gases generated in the furnace will be directed towards the centre of the furnace, i. e. towards the cave 6 under the hood 7 from where they escape through the outlet 8. The material passing downwards into the furnace along the furnace Walls will not be subjected to any intense preheating as the gases pass upwards towards the central parts of the furnace and here get an opportunity of preheating that portion of the material which is mostly in need of a preheating, i. e. the materlal passing more rapidly through the furnace. The result is a uniform heating of all the material in the furnace.

It is evident that the gases in a known way can be directed to different parts of the material passing through the furnace, for instance by placing a number of valves 12 at the lower edge of the gas outlet 7 controllable from the outside as at 12. If for instance the tempei'ature in a certain place becomes too high certain valves are closed so that the gas is directed to other valves through other parts of the mass in the furnace.

What we claim is 1. A charging hopper for electric furnaces, comprising a distributing member arranged at the upper end of the furnace and diverging downwardly, a gas outlet arranged beneath said distributing member and converging upwardly, and an outlet pipe connected with the upper part of said gas outlet, and means associated with said gas outlet for directing the gases to different parts of the material in the furnace.

2. A charging hopper for electric furnaces, comprising a distributing member arranged at the upper end of the furnace and diverging downwardly, a gas outlet arranged beneath said distributingmeinber and converging upwardly, an outlet pipo connected wit the upper part of said gas outlet, and a valve arranged in the gas outlet for directin the gases to different parts of the material in the furnace;

3. A charging hopper for electric furnaces, comprising a distributing member arranged at the upper end of the furnace and diver in downwardly, the lower edges of the distributing member being spaced from the walls of the furnace, a gas outlet arranged beneath said distributing member and converging upwardly, and an outlet pipe connected with t e upper part of said gas outlet, and means associated with said gas outlet for directing the gases to different parts of the material in the furnace.

4. A charging hopper for electric furnaces, comprising a distributing member arranged at the upper end of the furnaceand diverging downwardly, a gas outlet arranged beneath said distributing member and convergin upwardly, said gas outlet being forme in sections, each having a valve controlled outlet, and an outlet pipe connected with the upper part of said gas outlet.

In testimony whereof, we have signed our names to this specification.

CARL THEODOR THORSSELII. EBEE CHRISTIAN BECK-FRIIS. ERNST ERIK DAVID EDLUNDIJI. 

